blob: 60397144564c95f899cc14c26164068986a81937 [file] [log] [blame]
* Firmware Interface Table support.
* Copyright (C) 2012 Google Inc.
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc.
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "fit.h"
/* FIXME: This code assumes it is being executed on a little endian machine. */
#define FIT_POINTER_LOCATION 0xffffffc0
#define FIT_TABLE_LOWEST_ADDRESS ((uint32_t)(-(16 << 20)))
#define FIT_TYPE_HEADER 0x0
#define FIT_HEADER_VERSION 0x0100
struct fit_entry {
uint64_t address;
uint32_t size_reserved;
uint16_t version;
uint8_t type_checksum_valid;
uint8_t checksum;
} __attribute__ ((packed));
struct fit_table {
struct fit_entry header;
struct fit_entry entries[];
} __attribute__ ((packed));
struct microcode_header {
uint32_t version;
uint32_t revision;
uint32_t date;
uint32_t processor_signature;
uint32_t checksum;
uint32_t loader_revision;
uint32_t processor_flags;
uint32_t data_size;
uint32_t total_size;
uint8_t reserved[12];
} __attribute__ ((packed));
struct microcode_entry {
int offset;
int size;
static inline void *rom_buffer_pointer(struct buffer *buffer, int offset)
return &buffer->data[offset];
static inline int fit_entry_size_bytes(struct fit_entry *entry)
return (entry->size_reserved & 0xffffff) << 4;
static inline void fit_entry_update_size(struct fit_entry *entry,
int size_bytes)
/* Size is multiples of 16 bytes. */
entry->size_reserved = (size_bytes >> 4) & 0xffffff;
static inline void fit_entry_add_size(struct fit_entry *entry,
int size_bytes)
int size = fit_entry_size_bytes(entry);
size += size_bytes;
fit_entry_update_size(entry, size);
static inline int fit_entry_type(struct fit_entry *entry)
return entry->type_checksum_valid & ~FIT_ENTRY_CHECKSUM_VALID;
* Get an offset from a host pointer. This function assumes the ROM is located
* in the host address space at [4G - romsize -> 4G). It also assume all
* pointers have values within this address range.
static inline int ptr_to_offset(fit_offset_converter_t helper,
const struct buffer *region, uint32_t host_ptr)
return helper(region, -host_ptr);
* Get a pointer from an offset. This function assumes the ROM is located
* in the host address space at [4G - romsize -> 4G). It also assume all
* pointers have values within this address range.
static inline uint32_t offset_to_ptr(fit_offset_converter_t helper,
const struct buffer *region, int offset)
return -helper(region, offset);
static struct fit_table *locate_fit_table(fit_offset_converter_t offset_helper,
struct buffer *buffer)
struct fit_table *table;
uint32_t *fit_pointer;
fit_pointer = rom_buffer_pointer(buffer,
ptr_to_offset(offset_helper, buffer,
/* Ensure pointer is below 4GiB and within 16MiB of 4GiB */
if (fit_pointer[1] != 0 || fit_pointer[0] < FIT_TABLE_LOWEST_ADDRESS)
return NULL;
table = rom_buffer_pointer(buffer,
ptr_to_offset(offset_helper, buffer, *fit_pointer));
/* Check that the address field has the proper signature. */
if (strncmp((const char *)&table->header.address, FIT_HEADER_ADDRESS,
return NULL;
if (table->header.version != FIT_HEADER_VERSION)
return NULL;
if (fit_entry_type(&table->header) != FIT_TYPE_HEADER)
return NULL;
/* Assume that the FIT table only contains the header */
if (fit_entry_size_bytes(&table->header) != sizeof(struct fit_entry))
return NULL;
return table;
static void update_fit_checksum(struct fit_table *fit)
int size_bytes;
uint8_t *buffer;
uint8_t result;
int i;
fit->header.checksum = 0;
size_bytes = fit_entry_size_bytes(&fit->header);
result = 0;
buffer = (void *)fit;
for (i = 0; i < size_bytes; i++)
result += buffer[i];
fit->header.checksum = -result;
static void add_microcodde_entries(struct fit_table *fit,
const struct cbfs_image *image,
int num_mcus, struct microcode_entry *mcus,
fit_offset_converter_t offset_helper)
int i;
for (i = 0; i < num_mcus; i++) {
struct fit_entry *entry = &fit->entries[i];
struct microcode_entry *mcu = &mcus[i];
entry->address = offset_to_ptr(offset_helper, &image->buffer,
fit_entry_update_size(entry, mcu->size);
entry->version = FIT_MICROCODE_VERSION;
entry->type_checksum_valid = FIT_TYPE_MICROCODE;
entry->checksum = 0;
fit_entry_add_size(&fit->header, sizeof(struct fit_entry));
static int fit_header(void *ptr, uint32_t *current_offset, uint32_t *file_length)
struct buffer buf;
struct cbfs_file header; = ptr;
buf.size = sizeof(header);
cbfs_file_get_header(&buf, &header);
*current_offset = header.offset;
*file_length = header.len;
return 0;
static int parse_microcode_blob(struct cbfs_image *image,
struct cbfs_file *mcode_file,
struct microcode_entry *mcus, int *total_mcus)
int num_mcus;
uint32_t current_offset;
uint32_t file_length;
fit_header(mcode_file, &current_offset, &file_length);
current_offset += (int)((char *)mcode_file - image->;
num_mcus = 0;
while (file_length > sizeof(struct microcode_header))
const struct microcode_header *mcu_header;
mcu_header = rom_buffer_pointer(&image->buffer, current_offset);
/* Quickly sanity check a prospective microcode update. */
if (mcu_header->total_size < sizeof(*mcu_header))
/* FIXME: Should the checksum be validated? */
mcus[num_mcus].offset = current_offset;
mcus[num_mcus].size = mcu_header->total_size;
/* Proceed to next payload. */
current_offset += mcus[num_mcus].size;
file_length -= mcus[num_mcus].size;
/* Reached limit of FIT entries. */
if (num_mcus == *total_mcus)
if (file_length < sizeof(struct microcode_header))
/* Update how many microcode updates we found. */
*total_mcus = num_mcus;
return 0;
int fit_update_table(struct buffer *bootblock, struct cbfs_image *image,
const char *microcode_blob_name, int empty_entries,
fit_offset_converter_t offset_fn)
struct fit_table *fit;
struct cbfs_file *mcode_file;
struct microcode_entry *mcus;
int ret = 0;
// struct rom_image image = { .rom = rom, .size = romsize, };
fit = locate_fit_table(offset_fn, bootblock);
if (!fit) {
ERROR("FIT not found.\n");
return 1;
mcode_file = cbfs_get_entry(image, microcode_blob_name);
if (!mcode_file) {
ERROR("File '%s' not found in CBFS.\n",
return 1;
mcus = malloc(sizeof(*mcus) * empty_entries);
if (!mcus) {
ERROR("Couldn't allocate memory for microcode update entries.\n");
return 1;
if (parse_microcode_blob(image, mcode_file, mcus, &empty_entries)) {
ERROR("Couldn't parse microcode blob.\n");
ret = 1;
goto out;
add_microcodde_entries(fit, image, empty_entries, mcus, offset_fn);
return ret;